These planets have all been discovered as a result of the Palomar survey of faint minor planets and subsequently identified with planets observed at other oppositions. In Sept. and Oct. 1960, T. Gehrels exposed 130 plates with the 122 cm Schmidt camera at Palomar. In the following years C. J. van Houten and I. van Houten-Groeneveld measured these plates astrometrically and photometrically at Leiden. P. Herget, Cincinnati, computed the orbits of the planets found on the NORC computer, Dahlgren, Virginia, USA.